Process of metal working and lubricant therefor



United States Patent 3,392,116 PROCESS OF METAL WORKING AND LUBRICANT THEREFOR Jean Claude Hornus, Neuilly-sur-Seine, France, assignor to Cegedur GP, Paris, France N 0 Drawing. Continuation-impart of application Ser. No. 346,068, Feb. 20, 1964. This application Aug. 11, 1966, Ser. No. 571,715 Claims priority, application France, Feb. 28, 1963, 926,356, Patent 1,357,798 5 Claims. (Cl. 252-18) ABSTRACT OF THE DISCLOSURE A lubricating composition suitable for metal working processes which comprises selected amines and their salts which are synergistic in combination with an alkynol and when used with a carrier substantially reduce annealing stains and disfigurement normally produced during metal working procedures.

This application is a continuation-in-part of application Ser. No. 346,068, filed Feb. 20, 1964, now abandoned.

This invention relates generally to a process for working metal and the provision of a lubricant therefor. More specifically, this invention relates to a process of metal working, particularly by cold working, wherein there is utilized a lubricating composition comprising certain amines, or salts thereof, in a novel synergistic combination.

The prior art lubricating compositions as used in metal working and particularly in cold working procedures have permitted fairly low deformations. Upon attempt to exceed these deformation limits, most frequently defects appear upon the surface of the metal being treated. These defects are, in the case of cold rolling, most commonly in the form of herringbone rolling marks. Moreover, when such deformed metal, as in the case of metal strips, is annealed after a rolling process, it has been found that there is a staining of the annealed surface caused by the cracking of the lubricant composition.

The cracking reaction, while evident in many hydrocarbon base lubricants or the like, has been found to be particularly severe in lubricating compositions containing fatty acids and their esters. The avoidance of staining by prior art lubricating compositions is often achieved by the expensive step of removal of the lubricant before an annealing step. The prior art has also shown that in certain instances annealing stains may be avoided by providing special lubricants which contain no fatty acid or ester thereof. This solution of the staining problem, however, is quite unsatisfactory since such fatty acids, their esters thereof, and their derivatives such as soaps, generally provide most convenient carriers for metal working lubricating compositions.

It should be stressed that the annealing stains are not corrosion stains but a superficial deposition of thermolytic, polymerized residues originating from the lubricating materials. Those skilled in the art are quite aware that by the selection and an avoidance of certain materials (as in the case of the fatty acids and esters above cited) there may also be avoided the annealing stains but this expedient is necessarily an uneconomical one since such specifically designed formulations are also quite expensive and raise the cost of the cold working process both to the producer and the ultimate consumer. It is also known that annealing stains may often be avoided by a controlled and/or specialized annealing procedure, including flash annealing as well as the use of annealing furnaces having a controlled atmosphere generally 3,392,116 Patented July 9, 1968 of a reducing character. However, as those skilled in the art are aware, such expensive special procedures are not of general utility. Further, prior art lubricating compositions of choice have failed, in the avoidance of annealing stains, when the worked metallic substrate is subsequently annealed by a simple thermal treatment in a conventional annealing furnace, obviously the most economical treatment possible in the art. While a distinction has been made between annealing stains and corrosion stains, there is, nevertheless, a frequent corrosion roblem arising from highly reactive byproducts of the cracking or thermolysis of conventional lubricating compositions. There is provided, according to the present invention, a novel and superior, yet highly economical and convenient, lubricating composition, particularly useful in the cold working of metals, which permits not only an enhanced cold reduction but also, surprisingly, a substantial absence of annealing and corrosion stains in a subsequent simple thermal treatment.

According to this invention there is provided in a process of working metal, particularly by cold working, the step which includes contacting the metal being worked with a composition comprising an amine having the formula where R, is an aliphatic substituent having between 4 and 22 carbon atoms, each of R and R is selected from hydrogen and an aliphatic substituent having between 4 and 22 carbon atoms, R, is the anion of an aliphatic organic acid containing less than seven carbon atoms, and x is 0 or 1. In one embodiment of this invention R is selected from the group consisting of myristyl, lauryl,

searyl and oleyl and combinations thereof and R is selected from the group consisting of acetate, propionate and butyrate. Preferred amines, according to the above formula, include myristyl amine acetate, lauryl amine acetate, myristyl amine propionate, myristyl amine butyrate, and tallow amine acetate, the latter being a mixed lauryl, myristyl, stearyl and oleyl compound derived from tallow fatty acids.

Metal working lubricating compositions, including the amines of this invention, are of special utility in avoiding annealing stains in metal working processes including cold rolling and annealing thereafter. This avoidance of annealing staining is apparent even in compositions incorporating fatty acids, their esters and other derivatives, which may all be included in the composition of the present invention as carriers or diluents therefor or as complementary additives.

The process and composition of this invention further permit deformations which have not generally been heretofore permitted in the prior art without disfiguring the treated metallic surface as, for example, by the formation of herringbone rolling marks. While the discussion herein is principally directed to cold rolling, the compositions of the invention are useful in the other cold working procedures, including hammering, forging, stamping, die-stamping, etc.

The amine lubricating compounds of this invention are preferably used in lubricating compositions further comprising a carrier therefor. The particular carrier which may be a simple or complex composition of liquid, pasty or solid characteristics may be selected by those skilled in the art according to the particular requirement of the process of this invention. Exemplary of satisfactory carriers according to this invention are water, natural and/or synthetic hydrocarbons, alcohols and/or polyalcohols, their derivatives, etc., natural and/ or synthetic fats, soaps,

etc. Hydrocarbon carriers such as kerosene and light oil are particularly desirable. The kerosene is preferably deodorized, that is, containing little or no aromatic constituents. As hereinabove stated, a particular advantage of the present invention is in the avoidance of annealing stains in lubricating compositions which may comprise fatty acids, their esters and their other derivatives such as soaps. In the lubricating composition of this invention the carrier is preferably present in an amount at least 50% by weight and the amine of this invention will be preferably be included in said composition in an amount not exceeding 8% by weight.

Further, according to this invention there is provided in the present composition and in synergistic combination therewith one or more complementary additives. These complementary additives may be selected from among alcohols or polyalcohols with straight or branched chains containing 8 to 18 carbon atoms; fatty esters derived from an organic acid containing 8 to 18 carbon atoms; organic hydroxy acids; polyisobutylenes, metalloido-organic compounds, particularly the art-recognized organic phosphorous compounds as, for example, tricresyl phosphate; solid state lamellar lubricants such as graphite, molybdenum sulphide; products known in other applications as porogenes a definition inclusive of appropriate blowing, poreforming, or related gas generating agents; etc.

In the case of the present invention the polyisobutylenes operate as porogenes since under the operating conditions of a conventional annealing process they depolymerize to yield the gaseous monomer from which they were formed. Obviously, insuch applications, other polymers possessed of lubricating properties and deploymerizable under conventional annealing conditions, to yield a substantially inert gaseous monomer, may otherwise be appropriate or convenient. While not intending to be bound by theory, it is applicants belief that such porogenes are particularly effective in the avoidance of annealing stainsby reason of their in situ depolymerization which serves both to destroy the integrity of solid state residues and simultaneously by gas generation cooperate in their removal. Also, in the instance of the annealing of a coil of metal, such porogenes are particularly advantageous in the explusion of traces of lubricant which remain captive between the tight turns of the coil prior ot reaching the cracking temperature. It has been observed that solid annealing residues, especially those derived from compositions according to the invention and further comprised of solid state lubricants, may be completely broken up into fine non-adhering powders by the simple inclusion of an appropriate porogene such as polyisobutylene.

The polyisobutylene should be selected so as to have a lubricating viscosity. The preferred polyisobutylenes will be oily polymers consisting essentially of a polymerized isobutylenes. Desirably the polyisobutylenes of choice are those having a very narrow, or minimal, distribution of molecular weight (of the individual polymeric molecular species contained in the polymer) about the mean molecular weight, which is to say that there is preferred a minimum deviation between the maximum molecular weights and the minimum molecular weights. While it is desirable that the polymer be of lubricating oil viscosity under the preferred operating conditions, it is not possible to give a maximum molecular weight limitation in example of the invention. While in certain applications it can be said that, in general, the mean molecular weights will desirably be not substantially greater than 5,000,'it is, nevertheless, possible, in accordance with the teachings of this invention, to utilize a polyisobutylene of lubricating viscosity and possessed of a higher molecular weight particularly in instances where there is as discussed hereinabove a minimal molecular weight distribution about the mean molecular weight.

Complementary additives which have been found to be particularly effective in the composition of this invention include, singly or in combination, aliphatic alcohols containing 8 to 18 carbon atoms and polyisobutylenes which in synergistic combination with the present composition have been found to confer valuable properties thereto as especially evident in the attainment of maximum deformation limits in cold rolling processes. In the preferred embodiment of this invention the complementary additive is selected from myristyl alcohol, lauryl alcohol, polyisobutylene, and combinations and mixtures thereof, the alcohols being included in a proportion by weight not exceeding 12% and polyisobutylene when present being in proportion by weight not exceeding 4%.

Particular embodiments of the preferred composition of this invention may be prepared according to the formulae below, wherein the carrier is preferably a hydrocarbon, such as light oil or kerosene:

FORMULA 1 +11% amine propionate or 0 a5 and a+bl0% +b% myristyl alcohol or 0 b8 by weight FORMULA 2 i +c% amine prop.onate or 0 c 8 and c+d+e +11% lauryl alcohol or 0 d7 +e% myristyl alcohol or 0 e 4 iFOR'MULA 3 +f% amine propionate or 0 f8 +5 lauryl alcohol or 0 g7 +11% myristyl alcohol or 0 h5 +j% polyisobutylene 0r 0 j4 15% by weigh-t Example *1 The following conventional formulation was used as a lubricant.

Percent by weight Light oil 94.4 Butyl stearate 4.0 Lanolin 1.3

A maximum cold rolling of 300%, computed according to the Grard formula Tricresyl phosphate was obtained. Annealing marks were pronounced.

Example 2 A lubricant of a conventional but more recent type,

showing lesser tendency to yield annealing marks, was prepared as follows:

Percent Deodorized kerosene 95.7 Butyl stearate 4.0 Tricresyl phosphate 0.3

A maximum cold rolling of was obtained.

Example '3 A first lubricant according to this invention was prepared as follows:

Percent Deodorized kerosene 97.0 Di(tallow) amine acetate 3.0

385% cold rolling was obtained.

20% by weight 1 Example 4 A second formula according to this invention was prepared as follows:

Percent Deodorized kerosene 91.5 Amine acetate derived from tallow 0.5 Lauryl alcohol 3.0 Myristyl alcohol 1.0 Polyisobutylene 4.0

800% cold rolling was obtained.

In the formula of Example 4, synergistic effects between the alcohols, the polyisobutylene and the amine can be ascertained. By way of example, the cold rolling percentages obtained either with alcohols alone, or the polyisobutylene alone as additives are as follows:

Example 5 Percent Decdorized kerosene 96 Lauryl alcohol 3 Myristyl alcohol 1 Cold rolling 200 Example 6 Percent Deodorized kerosene 96 Polyisobutylene 4 Cold rolling 140 The amine products and additives according to the invention can be introduced either as a solution, a dispersion, or an emulsion in the diluents or carriers the non-restrictive list of which is given above. According to requirements, there can also be added emulsifying agents, anti-oxidants, antiseptics, wetting agents, polyfunctional products, etc.

If the deformation is to be followed by heat treatment in which the occurrence of marks due to lubricants must be avoided, the amine and additive compounds being eliminated (for instance through distillation, thermolysis into lighter, more fluid or even gaseous compounds, etc.) at a temperature lower than that required for the heat treatment, the number of carbon atoms and the type of chain of such compounds may be selected by those skilled in the art according to the temperature required for treatment.

It will often be found convenient to provide a filtering and purifying system for continuous metal Working in order to extend the lifetime and maintain the purity of the lubricant of this invention.

That which is claimed is: 1. A metal working lubricant suitable particularly for metal cold-working comprising:

(a) an amine salt having the formula 4T2 (R1-IIIH)R4 where R is an alkyl substituent having between 4 and 22 carbon atoms, each of R and R is selected from hydrogen and an alkyl substituent having between 4 and 22 carbon atoms, R is the anion of an alkanoic acid containing less than 7 carbon atoms; and said amine salt being present in an amount not exceeding about 8% by weight of said composition, (b) an alkanol containing 8 to 18 carbon atoms, said alkanol being present in an amount not exceeding about 12% by Weight of said composition,

(c) a polymerized isobutylene of lubricating oil viscosity being present in an amount not exceeding about 4% by Weight of said composition, and

(d) a major amount of carrier.

2. The composition of claim 1, wherein said amine salt is selected from the group consisting of myristyl amine acetate, lauryl amine acetate, myristyl amine propionate, myristyl amine butyrate, and tallow amine acetate; and said alkanol is selected from the group consisting of myristyl alcohol, lauryl alcohol, and combinations thereof.

3. A composition according to claim 1, further comprising a lubricant selected from the group consisting of organic phosphates and solid state lamellar lubricants.

4. A composition according to claim 3, wherein said lubricant is tricresyl phosphate of lubricating oil viscosity.

5. A composition according to claim 3, wherein said lubricant is a solid state, lamellar lubricant.

References Cited UNITED STATES PATENTS 2,228,325 1/1941 Olin et al 25234 X 2,833,721 5/1958 Hilliker et a1 25259 X 2,842,837 7/1958 Huet et al 25229 X 2,909,489 10/1959 Fields 25249.8 X 3,075,026 1/1963 Banks 25259 X FOREIGN PATENTS 705,194 3/1954 Great Britain.

750,340 6/1956 Great Britain.

884,442 12/1961 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

PATRICK F. GARVIN, Examiner. 

